Smart card comprising integrated circuitry including EPROM and error check and correction system

Abstract

A smart card having integrated circuitry including a single chip embedded microcontroller for controlling all processes and transactions that take place on the card. The single chip embedded microcontroller comprises a processor, a non-volatile erasable PROM communicating with the processor for reading and writing information to and from the PROM, and an error check and correction circuit cooperating with the PROM to correct errors occurring during the read and write operations after the PROM has performed a greater number of read and write cycles than its endurance. By such arrangement, the accuracy of the read and write operations on the smart card is maintained beyond the endurance of said PROM, enabling PROM-based smart cards having endurance on the order of 100,000 read and write cycles.

We claim: 
     
       1. A smart card, comprising: integrated circuitry including a single chip embedded microcontroller for controlling all processes and transactions that take place on the card, wherein the single chip embedded microcontroller comprises: a processor;   a non-volatile erasable PROM communicating with said processor, said processor capable of reading and writing information to and from said PROM in successive read and write operations; and   an error check and correction circuit cooperating with said PROM to correct errors occurring during the reading and writing of said information to and from said PROM after said PROM has performed a greater number of read and write cycles than its endurance whereby the accuracy of said read and write operations on the smart card is maintained beyond the endurance of said PROM.     
     
     
       2. The smart card of claim 1 in which said processor is capable of reading and writing information to and from said PROM in block segments of multiple bytes. 
     
     
       3. A smart card, comprising: integrated circuitry including a single chip embedded microcontroller for controlling all processes and transactions that take place on the card, wherein the single chip embedded microcontroller comprises: a processor,   a FLASH EPROM communicating with said processor, said processor capable of reading and writing information to and from said FLASH EPROM, and   an error check and correction circuit cooperating with said FLASH EPROM to correct errors occurring during read and write operations comprising the reading and writing of said information to and from said FLASH EPROM after said FLASH EPROM has performed a greater number of read and write cycles than its endurance whereby the accuracy of said read and write operations on the smart card is maintained beyond the endurance of said FLASH EPROM.     
     
     
       4. The smart card of claim 3 in which said processor is capable of reading and writing information to and from said FLASH EPROM in block segments of multiple bytes. 
     
     
       5. The smart card of claim 4 in which said smart card has an endurance of at least 78,000 read/write cycles. 
     
     
       6. The smart card of claim 1 in which said FLASH EPROM has an effective endurance of less than 78,000 read and write cycles. 
     
     
       7. A method of extended endurance operation of a smart card, comprising: providing a smart card as in claim 1;   operating said processor in said smart card to read and write information to and from said non-volatile erasable PROM in successive PROM read and write cycles; and   checking information errors in each PROM read and write cycle exceeding the PROM's effective endurance and correcting said errors with said error check and correction circuit, to maintain the accuracy of said read and write operations longer than the effective endurance of said PROM.   
     
     
       8. A method of extended endurance operation of a smart card according to claim 7 in which said processor reads and writes information to and from said non-volatile erasable PROM in block segments of multiple bytes. 
     
     
       9. A method of extended endurance operation of a smart card according to claim 7 in which said non-volatile erasable PROM is a FLASH EPROM. 
     
     
       10. A method of extended endurance operation of a smart card according to claim 9 in which said processor reads and writes information to and from said FLASH EPROM in block segments of multiple bytes. 
     
     
       11. The method of extended endurance operation of a smart card according to claim 7 in which said smart card has an endurance of at least 78,000 read and write cycles. 
     
     
       12. A method of extended endurance operation of a smart card, comprising: providing a smart card as in claim 1;   operating said FLASH EPROM in said smart card so that the number of FLASH EPROM read and write cycles; and   checking errors in each FLASH EPROM read and write cycle exceeding the FLASH EPROM's effective endurance and correcting said errors with said error check and correction circuit thereby allowing said smart card to maintain the accuracy of said read and write operations longer than the effective endurance of said FLASH EPROM.   
     
     
       13. A smart card according to claim 1, having an endurance of at least 78,000 read and write cycles. 
     
     
       14. A smart card according to claim 1, having an endurance in a range of from 78,000 to 100,000 read and write cycles. 
     
     
       15. A smart card according to claim 1, wherein the smart card contains no EEPROM components. 
     
     
       16. A method according to claim 7, wherein the smart card has an endurance in a range of from 78,000 to 100,000 read and write cycles. 
     
     
       17. A method according to claim 7, wherein the smart card contains no EEPROM components. 
     
     
       18. A method according to claim 7, wherein the smart card (i) has an endurance in a range of from 78,000 to 100,000 read and write cycles, and (ii) contains no EEPROM components. 
     
     
       19. A method according to claim 12, wherein the smart card has an endurance in a range of from 78,000 to 100,000 read and write cycles. 
     
     
       20. A method according to claim 12, wherein the smart card contains no EEPROM components.